Thermostat



L. J. GREENAWALT Dec. 29 I THERMOSTAT Filed April 29, 1922 INVENTOR Lewis J. Greenawait.

\NITNESSESZ ATII'ORNEY an v Fi -"Wis I the United 5;. 0 Man? bid in the Comm 0 lie of Shim have invented 9 Zmproven'aen'i: hermcs the following scifiz l y invenfiml appamfius and 'partifm contrelling devices, its objects to prov temperatureweptro mnnmum number Axmther object file a thermostat t as to permit arm having IP39 (final-y mam. stare mum operating 4 up *enipemtusd 0 In "aracilci suitabie her arm com can ably connect. a A 711211111211 m ustz. toncact lever arm nun 1y mmmted 0 1 e manuaily av a spring bein zmviied in I win aha csntact nlem'bar an arm in normai opera? the coniiaet member on t] afifie arm. A stop memos the eu'fer end 01 the uufd manually usla bie the IL. the-N 5.

in the singie skeet Figura 1 is a viizw a device embadying in parts being cut 831 8.1

Fif. 2 is a ViGT'T )orfiion of Hm w takefi 011 the ii 9 H on thereon by a 3'?" A nexible concnds connected to a I? is coinwcted minnl member 39 mounted. the casing 11,

of the device will be de- 'Ijllfi'l wit 1 reference "to no l *e or furnace, repnerally by 1-.- numeral 4-). in Fig. orovided with a heating element evice embodying my invention is trollinga circuitrincc comprising a snap switch v 7 motor: so, a. device which is illustrated and claimed in ation, Fierial No. 328 033, by R. 1a.. Bolze and E" W. gned to the Westingiionso filed. @cti 1919 Denman; and as Electric 6: l /lanuiacturing Company,

In the posiiion of the switch. 43 illustrated in the drawing, a circuit is established beiwcenthe positiveconductor 45 of the supply circuit through the resistor 42 to negative supply circuit conductor 4:6. if it is assun'sed that the thermostat illustrated in Fig.1 of the drawing; be applied to the fun nace hen both it and the furnace are at sub stantially room temperature it is evident that position of the thermally controlled arm will be substantially that illustrated in Fig. 1 of lll'l drawing, that is, at one end oi its turning movement. As the temperature of the furnace or of the elec'tlically heated device increased by reason. of the energization of the heating element 42, it being assumed that the"circuit has been closed thorethrough, as illustrated in Fig 3, the arm 14: is given a turnin movement on its axis under the influence on: the bimetallic strio 15 until integral abutment 4'?" located immediately adjacent the free end thereof engages the member and causes the contact rminai so be disengaged from the contact member A still further increase of temperatur causes flu her turning movemen o", no arm 14, and the engagemenx of the con c" ..ncmber 1'7 with the conmcmbez" closes a control circuit substantially as follows: from the supply-circuit conductor through a conductor 48 to contact terminal 19 and conductor 18 to the lever arm 14: 4 cont-act members 17 and 24, lever arm 21, conductor 25 terminal 26, a conductor 4-9, through the armature and field "winding; of the motor 44 to the supply con-- doctor 16, causing the motor cooperate to move the contact bridging member 51 to a "position substantially from that illustrated inthe drawing, thereby interrupting i'hc circuit through the heating element the temperature of the device 41 is reowing to deenergization of the u; clear-nit 4i? the lever arm 14 is caused YEW/6 in clockwise direction, thereby initially disengaging the contact member i? from the contact member and then For mitting the arm 27 to have a turning move- I While I have illustrated a ii-articular type of switching means, as actuated by the device embodying my invention, I do not dc c to be restricted thereto, as any suitable or dwsired switching means may be emplowdv The device embodying my invention thus provides a thermal indicating and controlling means in which a thermally contrv lcd lever arm has entire freedom of t-ur m n'iovement between normal room ten tors and the maximum operating tempt-(1; tors of the device with which it is to be 0 eratively associated and no complicated linh' motion orlosbmotion mechanism necessary.

Various modifiqationsmay be made in the device embodying my invention without lo-- parting from the spirit and. scope thereof and I desire that only such limitations shall be placed -thereon as are imposed by the prior art or are specifically set forth in the appended claims.

I claim as my invention:

combined temperature-indicating, limiting controlling device, comprising a bizlnua'lly'adjustable member having;- a plurality oi cont a ctiznembers' thereon, an auxiliary arm insulated from and carried by said. adjustable member and having a contact 'inember normally resiliently engaging one of tllQ- CODtRClJ members on said. adjustable member, an indicating member having a contact member thereon and thermally responsive means for controlling the position of said indicating member and cfi'cctive to cause the contact member thereon to engage the other of said contact members on said adfnstable arm at a predetermined temperzn sure.

2. A combined temperature-indicating, limiting, and controlling device, comprising a manually adjustable member having a plurality of contact members thereon, an auxiliary arm insulated from and carried by said adjustable member and having a contact member normally resiliently engaging one of the contact members on said adiustable member, a spacing member on said auxiliary arm, an indicating member having a contact member thereon and thermally responsive means for so moving said indicating member with an increa of temperature as to cause it to initially operativcly engage said spacing member to thereby disengage the Contact n'lember on the auxiliary arm from the contact member on the adjustable ff r" member and to cause the contact member on the indicating member to operatively engage the other contact member on the adjustable arm. 1

3. In a combined temperature-indicating, limiting and controlling device, in combination, a manually adjustable arm, an auxiliary arm secured on and-insulated from said adjustable arm, co-operating contact members on said adjustable and said auxiliary arm normally in engagement, a thermally controlled arm having a contact member thereon and movable in accordance with an increase of temperature to initially disengage said contact members and, upon further increase in temperature, to cause the contact member on said thermally controlled arm to engage the contact. member on said adjustable arm.

4. In a combined temperature-indicating, limiting and controlling device, in combination, a manually adjustable arm having a contact member thereon, an auxiliary arm pivotally mounted on and insulated from said adjustable arm and having a contact member normally resiliently engaging the contact member on said adjustablearm, and an arm movable in response to increase in temperature and having a contact member and means thereon for initially interrupting the engagement between the contact mem-- )ers on the adjustable and the auxiliary arms, and operative, upon further increase of temperature, to cause the contact member thereon to engage the contact member on the adjustable arm.

5. In a tombined temperature-indicating, limiting and controlling device, in combina tion, a normally adjustable two-part arm, the two parts being insulated from each other and each having co-operating contact members, resilient means for normally causing said contact members to engage, and a thermally controlled arm having a contact member and responsive, upon increases in temperature, to cause the contact members on said two arms to disengage and then to cause the contact member on the thermally controlled arm to engage the contact member on the manually adjustable arm.

6. In a combined temperature-indicating, limiting and controllingdevice, in combination, a normally adjustable two-part arm, the two parts being insulated from each other and each having co-operating contact members, resilient means for normally causing said contact members to engage, a thermally controlled arm having a contact member and responsive, upon increases in temperature, to cause the contact members on said two arms to disengage and then to cause the contact members on the thermally controlled arm to engage the contact member on the normall adjustable arm, and means for varying t 1e temperature interval between the disengagement and the engage-- ment of the respective co-operating contact members.

In testimony whereof, I have hereunto subscribed my name this 22 day of April,

LEWIS J. GREENAWALT. 

